In the parent patent application, I describe the construction of a soil penetrating head of various configurations which is driven into the soil and simultaneously draws a geothermal conduit loop. The soil penetrating head and conduit loop remain in the soil after it is driven thereinto by a force transmitting shaft, such as driven by a drill or a percussion apparatus. This method of disposing conduit loops into the ground greatly facilitates the installation of the loop in soft soil and reduces costs considerably.
In my U.S. application Ser. No. 12/497,560, filed on Jul. 3, 2009, and entitled “Soil Penetrating Plate Assembly To Position Geothermal Conduit Loops In Soil”, I disclose other embodiments of soil penetrating plate assemblies to draw the flexible geothermal conduit loops into the soft soil and to release them therein. With many of these installation procedures, the boring head and the soil penetrating plates to which the conduit loops are attached are simply left buried into the soft soil by detaching the force transmission shaft assembly therefrom. This has proven to be a good procedure for soft soil conditions but not feasible for hard soils where a drill head is required to bore into the soil.
When boring in dense soil and rock, the procedure to install geothermal conduits is to firstly bore a hole and retract the drill head and install a conduit loop hook to draw a conduit loop in the bore hole and again retract the shaft and head attachment. A filler material, such as cement, is then introduced in the bore hole. This is a time consuming task as these bore holes may be up to 500 feet deep and the shaft may be in five foot sections requiring at least two assemblies and disassemblies. Such installations are therefore very costly. Also, if the cement is injected from the bottom, another conduit needs to be positioned in the bore hole and retracted slowly as cement is injected in the bore hole.